1. Field of the Invention
This invention relates generally to fluid delivery systems, and more particularly to systems and methods for monitoring conditions of filter elements in fluid delivery systems.
2. Description of Related Art
Many fluid delivery systems (e.g., systems for moving gases such as air and liquids such as water) include filter elements (i.e., filters) at or near fluid inlets for removing particulates from the fluid. Removing such particulates not only improves fluid quality, it also prevents the particulates from building up on system components in contact with the fluid. Such buildup reduces system performance and is generally difficult to remove. For example, a typical heating, ventilating, and air conditioning (HVAC) system includes a filter at or near an air inlet for removing particulates from the air such as dust, pollen, etc. Removing such particulates not only improves air quality, it also prevents the particulates from building up on system components in contact with the air. Such buildup reduces the ability of the HVAC system to circulate air, and is generally difficult to remove.
As a filter removes particulates from a fluid over time, the filter eventually becomes clogged with the particulates (i.e., becomes “dirty”), and fluid flow through the filter is reduced. If the filter is allowed to become completely clogged, fluid flow stops. It is generally well known that filters must be either cleaned or replaced when fluid flow is sufficiently reduced by a buildup of particulates.
As it is generally difficult to determine the condition of a filter, most filter replacements are performed on a time basis (HVAC filters), a distance basis (automobile oil filters), or a total-operating-hours basis. Such filter replacement schedules tend to be conservative. It is also true that many fluid delivery system users tend to be lax about filter replacements, often resulting in reduced system performances.
There is thus a need for a system and method for determining the condition of a filter. The present invention fulfills this needs and provides further related advantages as described in the following summary.